Key phrase or hot word detection systems may be used to detect a word or phrase or the like, which may initiate an activity by a device. For example, the device may wake (e.g., transition from a low power or sleep mode to an active mode) based on the detection of a particular word or phrase. Such wake-on-voice or key phrase detection systems may focus on detection of a specified phrase in order to wake the device with restricted memory and compute power. It may be the goal of such systems to minimize two possible error types: false rejects (e.g., falsely rejecting a correct phrase) and false accepts (e.g., falsely accepting a wrong phrase). In particular, such false accepts may be more likely to occur when a portion of an uttered phrase matches or is phonetically similar to the key phrase while another portion of the uttered phrase does not match or is not phonetically similar.
As such, existing techniques may provide relatively high false positive rates particularly when a portion of a key phrase has been uttered. Such problems may become critical as the desire to implement key phrase detection systems such as wake on voice systems becomes more widespread.